Duct booser fans?

[jeff000]

Ok not really a garage question, but heating and AC question.

I saw a 4" duct booster fan for sale yesterday while looking for something else, and wondering how effective these actually are.
I have a 2300sq ft 2 story, and the furnace is the opposite corner of the house as my master bedroom.

I want more cold air into my bedroom with the AC on, I assume in the winter I may want more heat, but not sure yet.

In the basement I know what duct goes up to the bedroom, I assume it stops at the kitchen too.

Right now I have almost all other vents in the house closed off, and the basement ones taped off. It helped pressure, but not enough, it stays a couple degrees Celsius warmer in the bedroom then the main floor. Actually the whole upstairs is warmer.

Anyone ever use these inline boosters? I'm a sparky, but see and wire boosters all the time in commercial.

 

[lzenglish]

I used them quite a bit myself, in "old" commercial building re-models, and they work fine, if you don't expect too much out of them. I have also installed one in my own home, on a new 10 foot duct run extension for my HVAC unit. They are cheap enough, to give a try, if you just need a little extra boost of cfm. IMO

Wayne

 

[pseudorealityx]

4" may be too small for a single bedroom. You may want to get a 6" version.

 

[truckman5000]

What you want to do is, hire a good hvac guy to look if you can easily install a zoned system. Like having a separate thermostat for the 2nd floor.
I see all the time what you described, and we either zone the system, or install a separate system in the attic.
Because a lot of contractors around here, dont know how to correctly size a system for 2 floors. Without zoning ect..After the fact customer isnt happy.

The zoning will automatically close/ open, "vents" if a call from the thermostat on either floor.
Contractors get away from not zoning systems because, building code only states you need heat. Heat rises, so on the 2nd floor. Usually is the correct temp for heat. Cool air drops, so the 1st floor would cool, but be warmer on the 2nd flr.

Take some pics of the ducting in your basement, ill be glad to help.
mike

 

[jeff000]

Zoning is exactly what I want to do, just wasn't sure it was possible.

Really as long as the work needed to be done is all in the basement I'll spend the money to zone it.

I will take some pictures tonight.

Also I will be insulating the basement ceiling when I finish it, but right now I have the cold air return taking up a lot of the joist space, is there a way to insulate where they use the whole joist space as the cold air return?

 

[NUTTSGT]

I bought one at HD a few years back. It was a waste of money. Now if they make a commericial unit that might be different.

 

[danski0224]

If the ductwork is done properly, you don't need duct booster fans or zoning.

Duct booster fans sold at home centers are garbage. Nicer ones are available, but (1) aren't cheap and (2) are noisy.

Zoning is a crutch for people that (1) can't do ductwork properly or (2) are too cheap to fix it properly.

Residential forced air systems are not yet capable of throttling output or adjusting capacity, so lots of energy is wasted in conditioning (heat or cooling) the small zone that is calling for heat or cooling.

 

[JimL]

They are good for making a bunch of noise, thats about it.

 

[steve308]

Re: Duct boosTer fans?

I had the opposite problem / ice cold in the bed rooms, hot in the new addition family room. At the advice of an ac guy I set the fan to “on” not “auto” and it’s made a big difference. Constantly moving air will feel cooler or hotter depending on the thermostat setting. Only on the hottest of days do I still think about a supplemental system. (like this past week)

 

[HVAC Phil]

Duct booster fans are a crock. Zoning systems are great for someone that doesn't know how to design duct work. They are more of a bandaid than anything. A properly designed duct system shouldn't have poor airflow here or there. Every new 2 story house i do, i have never had more that a 3* difference from up to down. A little balancing on the system gets it right on.

 

[JimL]

Duct booster fans are a crock. Zoning systems are great for someone that doesn't know how to design duct work. They are more of a bandaid than anything. A properly designed duct system shouldn't have poor airflow here or there. Every new 2 story house i do, i have never had more that a 3* difference from up to down. A little balancing on the system gets it right on.

3 degrees is a lot. We zone any new house with 2 or more levels. Each zone designed to handle 100% system capacity, even though with staged equipment it doesn't really need to. I don't think zoning is a bandaid. Zoning or 2 separate systems is the only way to control temp on separate levels.

 

[pseudorealityx]

HVAC zoning is now a CODE requirement for multi-story buildings, including residential. That can be done either by motorized dampers, or more commonly, multiple units. It's also just more intelligent design.

Setting up zones with the capacity to handle the entire system capacity is a waste of ductwork IMO.

Booster fans can help in certain situations. Just dampering down all the other diffusers and registers to get airflow down at the far side of the building is increasing static pressure throughout the entire system. Which means you're increasing duct leakage, as well as reducing total airflow, which is about the last thing a residential system needs, since it already probably has pretty crappy ductwork design, due to residential construction.

Replacing ALL the ductwork may be the 'best' solution, but it can get very expensive.

 

[pseudorealityx]

Re: Duct boosTer fans?

I had the opposite problem / ice cold in the bed rooms, hot in the new addition family room. At the advice of an ac guy I set the fan to “on” not “auto” and it’s made a big difference. Constantly moving air will feel cooler or hotter depending on the thermostat setting. Only on the hottest of days do I still think about a supplemental system. (like this past week)

You'll also always be filtering the air, so it's cleaner.

 

[JimL]

HVAC zoning is now a CODE requirement for multi-story buildings, including residential. That can be done either by motorized dampers, or more commonly, multiple units. It's also just more intelligent design.

Setting up zones with the capacity to handle the entire system capacity is a waste of ductwork IMO.

Booster fans can help in certain situations. Just dampering down all the other diffusers and registers to get airflow down at the far side of the building is increasing static pressure throughout the entire system. Which means you're increasing duct leakage, as well as reducing total airflow, which is about the last thing a residential system needs, since it already probably has pretty crappy ductwork design, due to residential construction.

Replacing ALL the ductwork may be the 'best' solution, but it can get very expensive.

Why is it a waste of duct?

 

[pseudorealityx]

Why is it a waste of duct?

Because you're using more/larger duct than you need to. It's not 'bad', but it's more than you need. It costs more, is harder to route through basements, attics, walls, whatever.

I think you're a lot closer to ideal than the "zoning is for people who can't design duct work" folks.

 

[JimL]

Last house I did, I ran duct for 3 ton upstairs and for the main level. Over size dampers after the pair of pants into transitions. Seems like If I don't the static ends up high on the smaller zone and things get noisy in high stage.

 

[truckman5000]

Around here, hvac guys dont do as above. They just run 6" flex squish on the outside walls. Onto the 1st floor system. Theres a million homes like this here. Plenty of people re-doing, by either zoning. Witch i dont like to do.
Ill eliminate the 6" and floor registers and make a chase if possible to get to the attic, and zone the system.

 

[JimL]

I see. We only use flex in attics if we use it at all. No duct board either. All metal here.

 

[danski0224]

HVAC zoning is now a CODE requirement for multi-story buildings, including residential.

Code requires sealed ductwork in my area.

No mention is made of sealed ductwork that actually works, though. It is possible to have ductwork that is leak-free, but doesn't flow air worth a darn.

Code is just the legal minimum standard.

 

[pseudorealityx]

Code requires sealed ductwork in my area.

No mention is made of sealed ductwork that actually works, though. It is possible to have ductwork that is leak-free, but doesn't flow air worth a darn.

Code is just the legal minimum standard.

Ok, so the 'legal minimum standard' would be to require zoning. Not really sure what your point was.

 

[danski0224]

A code requirement for zoning does not mean that the ductwork is designed/installed properly or that the equipment will operate (1) efficiently as designed or (2) at rated capacity.

It is possible to install a zoned system with ductwork that is sealed, but still doesn't work worth a dam.

 

[A_Pmech]

Ditch the central air. It's so 1960's!

Install a multi-zone mini split. Problem solved! Plus, they're quieter, they don't pump dust around the house and they don't provide enormous caverns for creepy crawlies to live in.

 

[jimindm]

I am no HVAC guy. It is easier to heat an area than it is to cool it. Your zoned systems, duct sizing, and all that makes little difference. In my experience, it is how to cycle the air in the area. You need returns upstair to allow that air to cycle. Especially in the summer. Most homes have an open stairway, you can blow all the cool air upstairs that you want. The cool air that is at the floor will come down the steps to be recycled. With out cold air returns you can blow all of the cold air upstairs that you want, if the air has to come down stairs to be recycled you have not fixed the real problem.

We have an old home that had a gravity furnace in it when we bought it. Busted it up and put a forced air HVAC system in. We have several little registers that just go through the main floor ceiling into the upstairs floor. The main floor has huge cold air returns and none upstairs. It was always warmer upstairs. We added on and I added some returns where I could and it made a huge impact. Still a temp differance, but not like before.

 

[HVAC Phil]

3 degrees is a lot. We zone any new house with 2 or more levels. Each zone designed to handle 100% system capacity, even though with staged equipment it doesn't really need to. I don't think zoning is a bandaid. Zoning or 2 separate systems is the only way to control temp on separate levels.

3 degrees is a lot, but that is with all dampers in the open position. Once i balance it, i mark the settings for the homeowner for the seasons. Once i do that, the temp from up to down is the same. Didn't need the zoning system, which saves the customer money. I do use zoning systems in a pre-exixting job that some hack previously designed the ductwork.

 

[JimL]

I would like to see that. I have never seen a multi level house that wasn't zoned be even temps all around.

You can even keep basements the same as main level during summer?

Our systems, you just set the stat for each zone and forget about it.

We do pipe in a lot of returns upstairs, thought that was common knowledge.

 

[pseudorealityx]

A code requirement for zoning does not mean that the ductwork is designed/installed properly or that the equipment will operate (1) efficiently as designed or (2) at rated capacity.

It is possible to install a zoned system with ductwork that is sealed, but still doesn't work worth a dam.

Anything in life can be done poorly. What is your point?

 

[pseudorealityx]

Ditch the central air. It's so 1960's!

Install a multi-zone mini split. Problem solved! Plus, they're quieter, they don't pump dust around the house and they don't provide enormous caverns for creepy crawlies to live in.

They aren't quieter in all applications.
They don't pump dust because they don't filter dust worth a ****.
They're not overly pretty, and for the OP, a terrible solution to "this one room down at the end is hot/cold".

 

[HVAC Phil]

I would like to see that. I have never seen a multi level house that wasn't zoned be even temps all around.

You can even keep basements the same as main level during summer?

Our systems, you just set the stat for each zone and forget about it.

We do pipe in a lot of returns upstairs, thought that was common knowledge.

That's exactly how my 2400sq ft house heats/cools. Temp is even from downstairs to upstairs. But it did require the duct work to be correct.

Now my basement stays about 3 degrees cooler in the summer, vents are closed with just returns open. I don't really use the basement though, the house is big enough.

 

[pseudorealityx]

That's exactly how my 2400sq ft house heats/cools. Temp is even from downstairs to upstairs. But it did require the duct work to be correct.

Now my basement stays about 3 degrees cooler in the summer, vents are closed with just returns open. I don't really use the basement though, the house is big enough.

So with using only duct sizes, can you explain how you get even temps in summer and winter?

Summer: 2nd floor needs more air since it has a roof load and cool air tends to fall.

Winter: heat rises and 2nd floor tends to be warmer than main level, so it needs less airflow. This made worse using gas heating with higher discharge temps.

What magic are you using?

 

[adamk16]

I have a duct booster that goes directly to one room. While it works great to the one room, that room becomes way too hot or way too cold (depending on heat/air) and doesn't seem to help the system as a whole.

On another note, full disclosure I work with Owens Corning, but we recently updated a couple sections on our website with additional information about tips and solutions revolving around our duct solutions and air ventilation. Figured I'd post the link and maybe you'll find some additional information you'd be interested in.

Hope it helps!

Owens Corning HVAC Duct Solutions

Thanks,

Adam
Owens Corning Digital

 

[lzenglish]

I have a duct booster that goes directly to one room. While it works great to the one room, that room becomes way too hot or way too cold (depending on heat/air) and doesn't seem to help the system as a whole.

Adam
Owens Corning Digital

Adam: I would Venture to say that the nay sayers on the booster fans have not even held one in there hands, let alone installed one. (no offense)

PS: There are at least 40 of them installed in the 2 million sqft. of buildings (18 total), that I was in charge of, and they still do what they were designed for, which is to give a little boost of cfm, when you are stuck with what you got!

Wayne

 

[JimL]

So with using only duct sizes, can you explain how you get even temps in summer and winter?

Summer: 2nd floor needs more air since it has a roof load and cool air tends to fall.

Winter: heat rises and 2nd floor tends to be warmer than main level, so it needs less airflow. This made worse using gas heating with higher discharge temps.

What magic are you using?

Won't happen.

I get people that complain all the time about a 3 degree colder basement. Zone it, make it whatever temperature you want.

 

[lzenglish]

Won't happen.

Well, I guess you are the man "Jim", but I Disagree with you 100%, for a couple of added cfm, for 25 bucks, to get by, untill the proper sized unit is installed!!

Wayne

 

[HVAC Phil]

So with using only duct sizes, can you explain how you get even temps in summer and winter?

Summer: 2nd floor needs more air since it has a roof load and cool air tends to fall.

Winter: heat rises and 2nd floor tends to be warmer than main level, so it needs less airflow. This made worse using gas heating with higher discharge temps.

What magic are you using?

It's not magic, i adjust the dampers for each run(as a zoning system would be). I simply balance the house. It was something i was taught 20 years ago how to properly heat/cool a house. Do you honestly think if my master bedroom were too hot in the summer that my wife wouldn't ***** about it?

Now i have used zoning systems in houses with duct work that i haven't designed.

 

[JimL]

Well, I guess you are the man "Jim", but I Disagree with you 100%, for a couple of added cfm, for 25 bucks, to get by, untill the proper sized unit is installed!!

Wayne

Last booster I put in. Customer bought all the parts, fan, elbows, pipe, control.

I installed it per the instructions with the fan. 6' from the boot.

When done, it wouldn't blow a sheet of paper off the top of the register, made the corner flap a bit.

I am far from the man. I have just seen a ton of houses with no zoning not keep the temperature in the house even. Contractor swore it would work fine.

Everything we have zoned has worked perfectly. Set the temperature in each zone or keep them all the same wether its upstairs, main level, basement, sunroom ect...

 

[pseudorealityx]

It's not magic, i adjust the dampers for each run(as a zoning system would be). I simply balance the house. It was something i was taught 20 years ago how to properly heat/cool a house. Do you honestly think if my master bedroom were too hot in the summer that my wife wouldn't ***** about it?

Now i have used zoning systems in houses with duct work that i haven't designed.

Yes, but the balance will only work in either summer or winter. I assume that you then RE-balance as the season changes. You're implying that you don't have to rebalance with the seasons, which is what I want you to explain.

Let's say you've got a 3 ton unit running at 1000 cfm. In summer, the 2nd floor needs 600 cfm, and the main floor needs 400 cfm. In winter, the 2nd floor is going to need less than 600 cfm, and the main floor is going to need more than 400 cfm to maintain even temperatures between floors.

If you're adjusting the dampers, then you're just manually doing what a zoning system does.

 

[pseudorealityx]

Last booster I put in. Customer bought all the parts, fan, elbows, pipe, control.

I installed it per the instructions with the fan. 6' from the boot.

When done, it wouldn't blow a sheet of paper off the top of the register, made the corner flap a bit.

The little crappy duct booster fans have VERY VERY little static. They aren't going to pull air through the entire system. They're meant to run near 0" ESP, and then they'll help push. It's a tiny little fix for spot problems, not a way to design a system. But if you've got a diffuser that will only push 75 cfm unless you close off every other diffuser in the system. And you really want 90 cfm, they can help in that type of situation.

 

[JimL]

My bathroom uses a 6" booster fan for the fart fan. It is a small squirrel cage blower. Expensive, moves some CFM's... You could go in there and die and never smell it

 

[6768rogues]

They work but they add noise.